The Japanese government plans to extend a state of emergency in and around Tokyo until the last week of September in a further bid to contain the coronavirus epidemic, the Mainichi newspaper reported.

Japan last month expanded emergency curbs to cover about 80 per cent of its population until Sept 12, but the number of severe cases and the strain on the medical system have not eased sufficiently in Tokyo and surrounding areas to allow the restrictions to be lifted, Reuters reports.

The government plans to extend them by about two weeks in Tokyo and neighbouring Kanagawa, Saitama and Chiba prefectures, the Mainichi said, without citing sources.

Under the state of emergency, the government has sought to reduce foot traffic by asking restaurants to shorten their hours and refrain from serving alcohol, and companies to let staff work from home more frequently.